The present invention relates generally to threaded fasteners and, more particularly, to threaded fasteners which include integral locking means for preventing the unintended disengagement of the fasteners once they have been threadedly engaged.
There are many applications where fasteners must remain locked together after the fasteners have been installed. In these applications, the fasteners are typically subjected to vibration which tends to act against the forces holding the fasteners together, for example, threaded fasteners tend to "back-off" or separate when subjected to vibration. In the past, a variety of devices have been employed, for example, permanent fasteners such as rivets, spot welds or the like. However, oftentimes threaded fasteners are preferred due to ease of assembly and the potential for easy removal of the fasteners if the need arises in the future. For threaded fasteners, locking arrangements include among others a large variety of lock washers, coating the threads of one or both fastener parts with locking material and cotter pins. A variety of threaded fastener locking arrangements including drive pins, locking nuts and the like are disclosed in the following U.S. Pat. Nos. 1,279,962; 1,357,331; 1,397,808; 1,609,563; 1,656,118; and, 2,203,219. Unfortunately, these and other known threaded fastener locking arrangements require parts in addition to the fasteners themselves and oftentimes are complicated and difficult to assemble and/or install.
Accordingly, there is a need for improved threaded fasteners which include integral locking means to substantially prevent the unintended disengagement of the fasteners once they have been threadedly engaged yet can optionally be formed so as to be easy to assemble and disassemble, if desired, preferably without requiring specialized tools or additional locking parts separate from the fasteners.